IOWA CITY, Iowa (AP) — Tyson Foods has fired seven top managers at its largest pork plant after an independent investigation confirmed allegations that they bet on how many workers would test positive for the coronavirus, the company announced Wednesday.

The company said the investigation, led by former U.S. Attorney General Eric Holder, revealed troubling behavior that resulted in the firings at the plant in Waterloo, Iowa. An outbreak centered around the plant infected more than 1,000 employees, at least six of whom died.

“We value our people and expect everyone on the team, especially our leaders, to operate with integrity and care in everything we do,” Tyson Foods President and CEO Dean Banks said in a statement. “The behavior exhibited by these individuals does not represent the Tyson core values, which is why we took immediate and appropriate action to get to the truth.”

Banks traveled to the Waterloo plant on Wednesday to discuss the actions with employees.

Tyson spokesman Gary Mickelson said the company will not release detailed findings of the investigation or the names of those fired, citing privacy concerns.

“We can tell you that Mr. Holder and his team looked specifically at the gaming allegations and found sufficient evidence for us to terminate those involved,” he said.

Tyson suspended several top officials last month and retained the law firm Covington & Burling LLP, where Holder is a partner, to conduct the investigation.

Former maintenance manager Cody Brustkern said he cooperated with the investigation but was fired from his job of 10 years on Tuesday night without explanation. He said executives were “protecting their brand” over their longtime managers.

“The way this was handled was very disappointing,” he said. “I still don't know why I was fired. It's crazy.”

Lawyers for the families of four deceased Waterloo workers allege in lawsuits that plant manager Tom Hart organized a buy-in betting pool for supervisors to wager on what percentage of plant workers would test positive for COVID-19.

Hart allegedly organized the pool last spring as the virus spread through the Waterloo plant and the broader Waterloo community.

A former supervisor described the wager to the plaintiffs' lawyers, saying he and nine others each put $10 into the pool while mass testing of workers took place. The winner who pulled a piece of paper with the correct percentage out of a hat got the $100 payout.

Mel Orchard, an attorney for the deceased workers' families, said the firings confirm the authenticity of some “ghoulish” allegations in the lawsuits. He said Tyson “gambled with workers’ lives” by downplaying the virus and not offering adequate safety precautions.

“I’m grateful that they might be getting to the bottom of it, but it’s way too late for some people,” he said. “I hope Eric Holder stays on this case and continues to investigate the real issue: How is it that more than one thousand employees at one plant got sick and many died?”

The lawsuits allege plant managers pressured employees to keep working, even through sickness, and that the company waited too long to shut down the plant to stem the outbreak.

Managers told workers they had a responsibility to stay on the job to ensure that Americans didn’t go hungry, even while they started avoiding the plant floor themselves because they were afraid of contracting the virus.

The lawsuits name Hart, Brustkern, managers John Casey and Bret Tapken and human resources director James Hook as defendants. Attempts to reach Hart, Casey, Tapken and Hook were not immediately successful.

Tyson vowed Wednesday to open more avenues for employees to communicate concerns, to create a working group to strengthen collaborations with community leaders and to reinforce the importance of its values. Banks said Holder’s team would help "look for ways to enhance a trusting and respectful workplace.”

The steps come as Tyson faces continued scrutiny over its COVID-19 response, and a debate over whether Congress and states should shield companies from legal liability tied to infected workers and customers.

New York City Comptroller Scott Stinger on Tuesday called on the U.S. Securities and Exchange Commission to investigate whether Tyson has made misleading disclosures to investors about its pandemic response.

“There is human cost to Tyson’s failures – preventable deaths, hospitalizations and sick workers. These failures have material impacts on its business operations that carry serious risks for shareholders,” he said.

Separately, the family of another Tyson Foods employee is alleging in a lawsuit that he died from COVID-19 after the meat processing giant failed to implement safety protocols to guard against the coronavirus at the plant in Storm Lake, Iowa, where he worked.

Michael Everhard, 65, of Fonda, died of COVID-19 on June 18, three weeks after being diagnosed with the virus. His family contends he became infected at the Storm Lake plant where he worked for 27 years, The Sioux City Journal reported.

The lawsuit, filed by Everhard’s three children, argues that Tyson and its managers required him and other employees to continue working in an environment “rife with coronavirus” and didn’t implement safety precautions to protect them from contracting the virus, Storm Lake attorney Willis Hamilton said.

Tyson spokeswoman Liz Croston said the company has implemented several measures at its facilities that meet or exceed federal guidance for preventing the spread of COVID-19.